Jean bernard biron



' ram gaunt Jffirlb.

JEAN BERNARD BIROIN, 0F OA'RPEINT IAS/rushes.

I Letters Patent No. 67,941, dated August 20, 185?. I

IMPROVEMENT IN msmrsessrmesun% op pg wooo AND OTHER Mammals To roan fills .Stlgebult mum In in limit was fiatmt ant making point it: me.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, JEAN-BERNARD Bmorgof Garpentras, have invented a New Bleaching Process cape,

ciallyapplicahlo to Wocd Pulp,- ;and also to other Fibrous, FilamcntouiLMaterial;for the Manufacture of Paper and Pasteboard;" and I hereby declarethat the following is a full, clear, andesactdcscription of the-same.

r This invention relates toun improved process for bleaching 'wood pulp, whereby the pulp preserves its strength and flexibility, generally much impaired by the-ordinaryprocessesQemployed,which involve r dp c'ated applications of acids, chlorine, andallzalics of considerable strength, impairing 'the'fibre-as well as enhancing the-cost of the pulp. i We My improved method of bleaching obviates both these objections to'the existing methods, andis applicable to pulp made-from all. species of trees having a soft, light fibre, inany of which, but for myjblea chiing process, could not b'eemployed in the manufacture of pulp.gonerally, 'in consequence of the necessity of employing a high temperature for the di'sagg e'gation of the fibres, whereby a tint js imparted to the pulp,increasingth9 diflicult y of the bl'caching operation. 1

I process isas follows: The wood to be converted into pulp is-to'he split o'r divided and freed from hick,

, .knots,'and core, and reduced to pieces of'ahout two'to three inches in each dimension. I prefer the r macerate the wood by steeping it for ahout n' monthin a preparationof guick-lime and water tlie lime in the proportion of from fifteenth eighteen-per cent. by weight of the tens. The immersion should continue until the wood is'so-saturated that it will sinlc tolthe bottom. r It is then-or, if desired, .without previously under: going the process of maceration--suh mitted tothe action of a'jverticnl inillstone turning in a trough containing the preparation aboveimentioned'. The woodthns'crushed and disaggregated is placed a heap on an ip'clincd I surface for the purpose of draining oil the lime-water, and after remaining there a few days is carried to a washing-frollen h'ence it issues partially bleached. The pulp is then placed in a vat and treated with a solotion'ofa sulph'urt of an alkali; tli'nt whicli I prefer to- 'em'ploy being the'pentas'nlphnret of otassium'hut the pen'tasulphuret of limefis niorecomniercially advantageous from its comparatively low price. The pulp being well stirred and thoroughly impregnated wit-hthis solution, I pour in a solutionpf sulphuric or muriatic alum Y or ncid -sulphate or hydrochlorate of alumina. Thersulphu're't is now at ,once decomposed, the acid eliminates the sulphurfrom its combinations and' forms a salt with its alkaliue base, and the sulphurcombines the hydrogen of the coloring matter of the wood, forming .sulphurotted hydrogen, the presence whereof is as cer- 'tained'by. its characteristic odor. V. g l. 1 I

Although it may he stated gencrallythat sulphuretted hydrogen is. evolved when an acid is poured into on alkaline sulphuret, yet in this case I do not doubt that the hydrogen going to form the sulphuretted hydrogen is derived-from the coloring matter of the wood, being convinced thereof from the bleaching or discoloration of thefibrefwhich immediately takes placewhen treated as above described, andthe wood pulp may now be associated with rag pulp or employed separately in the manufacture of paper. The quantities to be employed of the various reagents, sulphateot' alumina and acids, above mentioned, 'will dpend on the g reater or less'degree of coloring of. .the yvood pulp when it issues from the millstone and rollers, and on the degree of whiteness desired to be obtained, and cannot, therefore, be exactly predicated, but approximatcly'the following are the proportions'I prefer to employ: 'Forfone part, by weight, of s'ulphuret, five partsof crystallized alum or live parts of hydrochloric acid of twenty-two degrees, or-three parts of sulphuric acid of sixty degrees of strength. The some wood is to be treated with four per cent. of pentasulphuret and twenty per. cent. of alum or twenty'pcr "cent. of hydrochloric held or twelve per cent. of sulphuric acid, and I then obtainawood pulp-\vhich,-mix ed with forty to fifty per cent. of rag pulp, will yield a paper :sulliciently white for newspapers and printing generally.

The bleaching action produced by the sulphuret on wood pulp will be proddced' more or less efliciently on any other textile material. On being first treated with this agent, and afterwards submitted to the action. of chlorine, they will acquire a notably superior: degree of whiteness to that given by chlorinealonc.

Another advantage of my; process is the preservative effect of the sulphate of alum employed, whereby the wood pulp may be indefinitely stored till wanted for use.

I do not confine myself -to theme of wood pulp alone vin the manufacture of paper and pastehoard, as any other fibrous filamentous materials may be subjected to the treatment herein described without departing from my'invention. A

I claim as new, and desire to secure by Letters Yatent- The employment, as a. bleaching agent, of alkaline sulphurets, in manner and for the purposes substantially as above setifortll and described. J. B. BIRQN.

Witnessesr Emnn Roux Amoco, 0. Muss. 

